Method of mixing and transporting concrete.



J. H. MACMICHAEL.

METHOD OF MIXING AND TRANSPORTING CONCRETE.

APPLICATION FILED AUG.4, 19H.

Patented May 30, .1916.

2 SHEETS-SHEET I.

J. H. MAcMICHAEL.

METHOD OF MIXING AND TRANSPORTING CONCRETE.

APPLICATION FILED AUG.4| 1911.

L T 0H 3% V: n Mn 0 @z n e t a P ITED SA I PATENT OFFICE.

JOHN H. MAOMICHAEL, oE-roLEno, OHIO, AssIGNOn, BY MEsNE ASSIGNMENTS, To

CONCRETE MIXING AN'D CONVEYING COMPANY, or CHICAGO, ILLINOIS, A CORPO-vention can be carried out.

RATION OF ILLINOIS.

METHOD OF MIXING AND TRANSPOBTING- CONCRETE.

To all whom it may concern:

Be it known that I, JOHN H. Mao

MICHAEL, a citizen of the United States, re-

siding at Toledo, in the county of Maumee and State of Ohio, haveinvented certain new and useful Improvements in Methods of Mixing andTransporting Concrete, of which the following is a specification,reference being had therein to the accompanying drawing.

T his invention relates to an improved method or process for mixingingredients, such as broken rock, sand, cement and water, used in themanufacture of concrete.

.The object of the invention is to produce a superior final product, toexpedite the making and delivering of the composition, and to economizein the manufacture.-

Figure l is a vertical section of an apparatus composed of parts wherebythe in.- Fig. 2 is an elevation of the same. Fig. 3 is a series ofdiagrammatic views illustrating the steps followed in the operation.

In the drawings, 1 represents a receptacle into which the ingredientsare fed, inp'redetermined proportions, such as to have them properlyrelatedto each other in producing the final concrete product. I preferto introduce them by means of a superadjacent hopper 2, into which theycan be thrown miscellaneously from barrows or other carriers.

Between the hopper 2 and the receptacle 1 there is a valve mechanism at3, which, as shown, is a rotary cylinder valve 4 with a large passageway5 therethrough, and mounted in an approximately cylindrical casing 6.This valve or cutoff 4 can be turned part way and Close the passage fromthe hopper 2 to the receptacle 1. Upon turning it part of a revolution,the valve opening or passage 5 is brought into aline- -ment with thebottomof the hopper and the top of the receptacle, and the loadcontained in the hopper can be instantly dropped into the latter. Thisform of valve enables me to provide an air-tight closure for thereceptacle 1.

It will be understood, as above indicated, that the rock, sand, cementand water, in suitable proportions, can be deposited in the hopper 2without paying attention to the manner in which they are mixed or com-Specifieation of Letters Patent.

- through Patented May 30, 1916.

Application filed August 4, 1911. Serial No. 642,400.

and commingling is attained at a later stage,

as will be below described.

The receptacle 1 is shown as cylindrical at the upper part 7, andtapering or coniform atthe lower part 8. It may taper from bottom .totop, but that is not essential, as satisfactory results are' Obtained solong as t e material finally passes through an orifice of suitable size,9. The walls of the receptacle at no point furnish any Obstruction inthe pathway for the material as it travels thevreceptac'le and thence tothe dis charge. I

10 indicates a discharge duct. It is of rela-' tively large size, fromsix to ten inches in diameter, and at its initial, or receiving end, 11,it is fitted tothe correspondingly sized orifice 9 at'the bottom of thereceptacle. At 12 this discharge duct 10 is cui'ved, so that the pathfor the material is changed from the vertical to the horizontal, 'oreven. to

an inclination upward. By having this conveying and discharging duct ofrelatively large diameter, it permits the mixing of the components ofthe concrete to be effected therein while the mass is being propelled orconveyed from the receptacle to the place of final deposit.

13 represents an air supply. Itmay be a tank 'orreservoir in which airis stored under compression, or a long main.

14 and 15, respectively, indicate air ducts leading from the air supply,That at 14 is connected, through the duct section 14 at the Orifice 18,with the space or region at 17 in the upper part of the receptacle 1,above the mass of material which is to be expelled therefrom.' The ductat 15 finally communicates through the duct section 15 with the chamberor region, inside of the initial, or receiving, end of the duct 10. Itis shown as so related to this duct that the air enters on linestangential to the first part of the path of the material.

It will be Seen that theair which enters the upper part of thereceptacle, through the pipe section lt at the orifice 18, merely I airwhich enters the initial end of the duct,

10, through the orifice at 16, enters with a very high velocity, theorifice being suitably reduced for the purpose of converting theoriginal pressureinto this highvelocity. In other words, the parts ofthe apparatus are so constructed and related that two bodies of air areutilized, at different points, respectively, along the path of theconcrete material, one air bodybeing applied under such conditions thatpressure is its principal working quality, while the other air body isutilized in such way that velocity is brought into play and madeavailable. The jet of air, entering at 16 with this high velocityimpinges with that velocity upon the small sub-masses of material whichdescend from the main chamber of the receptacle 1, and, immediately,these smaller sub-masses of material attain a high velocity correpart ofthe receptacle through the ori ce 18 (which air, as above remarked, maybe of initially the same pressure, substantially, as that of the airwhich is supplied for the jet at 16), is, by the mere pressure which itexerts, forcing the masses of material in the receptacle downwardthrough the converging passageway 8 into the initial end of the duct 10,and into the path of the air jet at 16. The jet of high velocity, suchas that which enters at 16, would not operate in the same way ifintroduced above the main body of the mass. And, vice versa, a mass ofair introduced 'at the initial end of the duct merely under pressure,and not under velocity, would not be as advantageous in advancing thematerial through the duct. The jet orifice at 16 can be of any wellknown suitable form, tapered or cylindrical, but should have a crossarea sufficiently reduced, relative to the cross area of the upper airchamber to give the proper jet effect.

It mustbe remembered that the materials in the mass (of such naturethat, when properly commingled and properly contacting with water, theingredients will form concrete are liable to set if they are permittedto stop, or are arrested at any point. The entire mass temporarily heldin the receptacle 1 (composed of the ingredients of concrete in theproper relative proportions) must be expelled therefrom and driven alongthe duct 10 to the place of delivery, in a few seconds of time. They arenot completely or thoroughly commingled when they are introduced intothe receptacle 1. In fact, my purposes and apparatus are such that thereneed be no preliminary mixing or commingling whatever. The severalingredients, in their properproportions, can

' be indiscriminately dumped or shoveled into the receptacle 1, with theassurance that before they reach the point of delivery at 19,

they will be mixed and mingled in a way that gives a concrete masssuperior to any produced by the concrete mixers heretofore used. But, asabove remarked, this operation of mixing and delivering must be donewith great rapidity, not only because of the fact that the mixedmass-must be put in its final place at as early an instant as possibleafter the contact of the water with the other ingredients, but alsobecause of the liability of the materials, as above described, to set or"harden at points along the'duct. And hence it is that great importanceis incident to the employing of air jet of high velocity at the initialend of the duct 10, and to the simultaneous downward feeding of the massin the receptacle 1 under the action of the pressure above.

The handling of the different parts of the apparatus in such way thatthe pressure in the initial end of the duct shall be properly related tothe pressure in the upper part of the receptacle 1, above the mass ofmaterial, is a matter of great importance. It is seen that the materialwhich is moving along the duct 10 tends to reduce the. velocity of theair from the orifice at 16 and to cause a back pressure, if the air ispermitted to accumulate. This back pressure, if great enough, will befelt in an upward direction at the bottom of the mass in thereceptacle 1. And the operation must be so carried on that this backward.or upward pressure shall not materially interfere with the downwardfeeding pressure exerted by the upper mass .of air at 17. The air at thebottom should act by its velocity as nearly exclusively as possible,for, in such case, the back pressure in the end of the duct 10 will beat its minimum, and the pressure at 17 in the upper part of thereceptacle can work with the greatest efficiency in rapidly the duct 10to the place of delivery 19, I

prefer to employ two air controllers or valves, as shown at 20 and 21.By means of that at 21, the operator can readily control the ,jets atthe receiving end of the duct,

while with that at 20, he can control the volume, and, to some extent,the pressure of the air which is introduced into the space 17, in theupper end of the receptacle.

Ordinarily the preferred steps in operation'are (after a mass ofmaterials of properly proportioned quantities have been introduced intothe receptacle 1) to first open the jet valve at 21. This begins to atonce impart velocity to the lowermost parts of the material, which havebegun to squeeze downward through the orifice 9, and to start a streamof this material through the duct 10. Immediately after this stream hasstarted, and the downward passing parts of the mass have. been put underthe inertia of.

propulsion, the valve at can be gradually andrapidly opened, and. avolume of air under pressure introduced to the space at 17, whichcompels the entire mass" to move downward, rapidly, into the path of theair jets at 16. I

\Vith a properly constructed and properly handled set of parts, arelatively large mass of material (one-fourth of a cubic" yard) can beejected from the receptacle 1, thoroughly mixed in the duct 10, and"delivered at a relatively great distance (three hundred and fifteen feetI have reached) in the period of from two to four seconds, with acomparatively low air pressure, eighty to one hundred and twenty pounds,in the main or supply reservoir 13.

Cement is one of the bodies which, upon the addition of water, tends tocrystallize and harden or set. If it be, mingled with pieces of rock, orthe like, the latter are firmly bound together upon the addition vofwater if the crystallizing or setting action can proceed withoutinterference. But if,

like, there is a fracturing of initial crystals and an interfering withthe fullest cohesion that is possible.

The water should be distributedfin the shortest possible time, andafter" the water and cement are distributed the movement of the solidpieces of said masses should be stopped and the concrete mass put intoposition as speedily as possible;

By the present method large masses can, in a few seconds, as abovestated, be completely hydrated and mixed and quickly put in position forsetting. Y

I do not limit, myself to the details of structure shown in theaccompanying drawings, as I carry out this process in mechanism ofeither of various forms.

I do not herein present claims for the apparatus which I have shown anddescribed, or for the mechanism in my earlier application 580,582,preferring to herein present claims which relate to the pneumatic mixing of the previously unmixed ingredients of the concrete whilepneumatically transporting them; and to claim the more specific mattersof method and of mechanism in said earlier application 580,582.

What I claim is:

- 1. The hereindescribed method of pneutioned to constitute a charge ofconcrete, to an an tight receptacle at the initial end of an elongated,confined relatively wide, pathway; and causing a body of air underpres-.

.maticallyconveying and mixing the ingredients of concrete, such as rockpieces, sand, cement and water and simultaneously producing' concretetherefrom, it consisting inv forming successive charges by supplying,for each charge, proportioned quantities of the rock, sand, cement andwater, initially separate from each other, to an air-tight receiver atthe initial end of an elongated, path-defining, relatively wide,conveying and mixing duct; and causing a body of air under pressure toimpinge upon the charge, prior to the complete commingling of thesub-masses thereof, at points near those where it enters thesaidconveying and mixing duct, andpropel and rapidly move the said chargethrough the said duct, thereby agitating the particles of the sub-massesarelatively to each other and efiecting the mixing of the saidproportioned sub-masses while pneumatically propelling them along thesaid duct. 3. The herein described method of pneumatically conveying andmixing the masses of the rock pieces, sand and cement, to- 105 getherwith water, constituting a charge of concrete, it consisting insupplying separate proportioned quantities of said rock, sand andcement, While dry or unmixed, and supplying a quantum of watertherewith, 110 to an air-tight receptacle having a receiving region andan elongated conducting region extending to the place Where the concretematerial is to be finally deposited; and.

causing a body of air under pressure to 5 impinge upon the charge, priorto the complete commingling of its sub -masses, at points near theinitial end of the conducting region, the said air propelling and rapdlymoving said charge along the conduct- 130 mg region, agitating, amongeach other. the particles of the said sub-masses, and efl'ecting themixing thereof in the proper proportions for concrete while propellingthem along said path.

4. The herein described method of pneumatically conveying and mixingmasses of rock pieces, sand, cement and water, propcrtioned toconstitute a charge of concrete, it consistingin supplying the masses186 of rock, sand, cement and water, prior,

rapidly moving said charge through said region and agitating theparticles of rock, sand, cement and water among each other, while beingpropelled along said region, to effect the mixing of the saidproportioned sub-masses.

5. The herein described method of pneumatically conveying and mixing thecomponents of a concrete mass, to-wit, rock pieces, sand, cement andwater, which consists in delivering to an air blast the said ingredientsprior to the complete commingling, causing the said air blast to alterthe distribution of the initially segregated rock and other materialsand forcibly advance them through a prolonged, relatively widened,pathway, and to commingle the said ingredients while they are beingforcibly advanced, and to finally deliver them, with the water and thechrystallizable ingredients uniformly distributed over the rock andother ingredients and with all the ingredients uniformly mingled in aconcrete mass.-

6. The herein described method of pneumatically conveying and mixingmasses of rock pieces, sand, water and cement, and simultaneouslyproducing concrete, it consisting in forming a charge by supplyingproportioned masses of said rock, sand, cement and water, to anair-tight receiver at the initial end of an elongated path-defining,relatively wide, conveying and mixing duct, causing the said charge, asan entirety and prior to the complete commingling of its sub-masses, tomove bodily from the re ceiver toward the said duct, and causing a bodyof air under pressure to impinge at points near the initial end of thesaid duct upon the charge, the said air propelling and rapidly movingthe said charge along the duct, agitating the particles of the submassesrelatively to each other, and efiecting the mixing of the saidproportioned masses while they are pneumatically propelled along theduct.

7. The herein described method of mixing and delivering the proportionedinitially separate masses of rock, sand, Water and cement finallyconstituting a charge of concrete, it consisting in supplying the saidmasses, prior to their complete commingling, to a partially obstructedor reduced path having a receiving region and a conducting region andextending to the place where the concrete material is to be finallydeposited, and causing a body of air under pressure to impinge upon themass prior to the complete commingling of the sub-masses, the said airpropelling, agitating and rapidly moving the mass and effecting themixing of the said proportioned sub-masses while propelling them alongsaid path.

8. The herein described method of preparing a finally mixedconcrete-like mass composed of proportioned sub-masses of rock, sand,cement and water, which consists in bringing them together, prior totheir complete commingling, in a path extending from a receiving regionto the place of final deposit and partially obstructed or reduced at oneor more points, and causing a body of air under pressure to impinge uponsuccessive portions of the mass prior to the complete commingling of thesubmingling, causing said air blast to alter the distribution of theinitially segregated rock material and commingle the said ingredientsWhile forcibly advancing them through a prolonged, relatively laterallywide path, which is partially obstructed or reduced at one or morepoints, and finally delivering them, with the water and the-crystallizable ingredients uniformly distributed over the rock andother ingredients and with all of the ingredients uniformly mingled in aconcrete mass.

10. The herein described method of mixing the rock, sand, cement andwater ingredients of a mass :from which concrete is to be formed, anddelivering the concrete at the place of final deposit, consisting indelivering to an inclosed chamber or duct having a receiving region andan elongated mixing region the unmixed incompletely mingled proportionedingredients for a concrete mass, subjecting small successive parts ofthe said ingredients immediately upon their passage from the receivingregion to the'mixing region and prior to their being mixed and mingledto the action of an air jet of high velocity, and causing said jet toeffect the complete mingling of the particles of the ingredient massesamong each other while they are being propelled through the said mixingregion, and simultaneously causing the initial mass in the receivingregion to move under air pressure to the points where the materialsenter the path of the said jet.

11. The herein described method of mixing the rock, sand, cement andwater ingredients of a mass from which concrete is to be formed, anddelivering the concrete at the place of final deposit, consisting indelivering to an inclosed chamber or duct having a receiving region andan elongated mixing region the unmixed incompletely mingled proportionedingredients'for a concrete mass, subjecting them to the action of an airbody under pressure and distributed in the receiving region over theentire mass therein and causing said mass to, move bodily from thereceiving region, deflecting the materials immediately on their leavingthe receiving region from the lines of their travel therethrough todifl'erent lines of travel through the mixing region, subjecting smallsuccessive parts of the said ingredi- L ents at the place of deflectionadjacent the mixing region to the action of an air jet 0f high velocitydirected along the second lines of travel, and causing theair to eflectthe mixing and complete mingling of the par ticles' of the ingredientmasses among each other while they are being propelled through themixing region.

12. The herein described method of mixing the rock, sand, cement andWater ingredients of a mass from which concrete is V to be formed, anddelivering the concrete at the placeof final deposit, consisting indelivering to an inclosed chamber or duct having a receiving region andan elongated mixing region the unmixed incompletely mingled proportionedingredients for a concrete mass, subjecting small successive parts ofthe said ingredients immediately upon their passage from the receivingregion to the mixing region and prior to their being mixed and mingledto the action of an air jet of high velocity, and causing said jet toeffect the complete mingling of the particles of the ingredient massesamong each other while they are being propelled through the said mixingregion, and simultaneously causing the initial mass in the receivingregion to move under air pressure to the points where the materialsenter the path of the said jet.

13. The herein described method of mixing the rock, sand, cement andwater gredients of a mass from which concrete is to be formed, anddelivering the concrete at the place of final deposit, consisting indelivering to an inclosed chamber or duct having a receiving region andan elongated mixing region the unmixed incompletely mingled proportionedingredients for a concrete mass, subjecting them to the action of an airbody under pressure and distributed in the receiving region over theentire mass therein and causing said mass to move bodily mixing andcomplete mingling of the particles of the ingredient masses among each'other while they are being propelled through the mixing region.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN H. MAoMICHAEL. Witnesses:

ADA LouIsE K 'rz, ANNA S. KATZ.

